2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[Name]{@Name@: to transmit name info from renamer to typechecker}
8 -- Re-export the OccName stuff
14 mkInternalName, mkSystemName,
15 mkSystemVarName, mkSysTvName,
16 mkFCallName, mkIPName,
17 mkExternalName, mkWiredInName,
19 nameUnique, setNameUnique,
20 nameOccName, nameModule, nameModule_maybe,
22 hashName, localiseName,
24 nameSrcLoc, nameParent, nameParent_maybe, isImplicitName,
26 isSystemName, isInternalName, isExternalName,
27 isTyVarName, isWiredInName, isBuiltInSyntax,
28 wiredInNameTyThing_maybe,
31 -- Class NamedThing and overloaded friends
33 getSrcLoc, getOccString
36 #include "HsVersions.h"
38 import {-# SOURCE #-} TypeRep( TyThing )
40 import OccName -- All of it
41 import Module ( Module, moduleFS )
42 import SrcLoc ( noSrcLoc, wiredInSrcLoc, SrcLoc )
43 import Unique ( Unique, Uniquable(..), getKey, pprUnique )
44 import Maybes ( orElse, isJust )
45 import FastString ( FastString, zEncodeFS )
49 %************************************************************************
51 \subsection[Name-datatype]{The @Name@ datatype, and name construction}
53 %************************************************************************
57 n_sort :: NameSort, -- What sort of name it is
58 n_occ :: !OccName, -- Its occurrence name
60 n_loc :: !SrcLoc -- Definition site
63 -- NOTE: we make the n_loc field strict to eliminate some potential
64 -- (and real!) space leaks, due to the fact that we don't look at
65 -- the SrcLoc in a Name all that often.
68 = External Module (Maybe Name)
69 -- (Just parent) => this Name is a subordinate name of 'parent'
70 -- e.g. data constructor of a data type, method of a class
71 -- Nothing => not a subordinate
73 | WiredIn Module (Maybe Name) TyThing BuiltInSyntax
74 -- A variant of External, for wired-in things
76 | Internal -- A user-defined Id or TyVar
77 -- defined in the module being compiled
79 | System -- A system-defined Id or TyVar. Typically the
80 -- OccName is very uninformative (like 's')
82 data BuiltInSyntax = BuiltInSyntax | UserSyntax
83 -- BuiltInSyntax is for things like (:), [], tuples etc,
84 -- which have special syntactic forms. They aren't "in scope"
88 Notes about the NameSorts:
90 1. Initially, top-level Ids (including locally-defined ones) get External names,
91 and all other local Ids get Internal names
93 2. Things with a External name are given C static labels, so they finally
94 appear in the .o file's symbol table. They appear in the symbol table
95 in the form M.n. If originally-local things have this property they
96 must be made @External@ first.
98 3. In the tidy-core phase, a External that is not visible to an importer
99 is changed to Internal, and a Internal that is visible is changed to External
101 4. A System Name differs in the following ways:
102 a) has unique attached when printing dumps
103 b) unifier eliminates sys tyvars in favour of user provs where possible
105 Before anything gets printed in interface files or output code, it's
106 fed through a 'tidy' processor, which zaps the OccNames to have
107 unique names; and converts all sys-locals to user locals
108 If any desugarer sys-locals have survived that far, they get changed to
111 Built-in syntax => It's a syntactic form, not "in scope" (e.g. [])
113 Wired-in thing => The thing (Id, TyCon) is fully known to the compiler,
114 not read from an interface file.
115 E.g. Bool, True, Int, Float, and many others
117 All built-in syntax is for wired-in things.
120 nameUnique :: Name -> Unique
121 nameOccName :: Name -> OccName
122 nameModule :: Name -> Module
123 nameSrcLoc :: Name -> SrcLoc
125 nameUnique name = n_uniq name
126 nameOccName name = n_occ name
127 nameSrcLoc name = n_loc name
131 nameIsLocalOrFrom :: Module -> Name -> Bool
132 isInternalName :: Name -> Bool
133 isExternalName :: Name -> Bool
134 isSystemName :: Name -> Bool
135 isWiredInName :: Name -> Bool
137 isWiredInName (Name {n_sort = WiredIn _ _ _ _}) = True
138 isWiredInName other = False
140 wiredInNameTyThing_maybe :: Name -> Maybe TyThing
141 wiredInNameTyThing_maybe (Name {n_sort = WiredIn _ _ thing _}) = Just thing
142 wiredInNameTyThing_maybe other = Nothing
144 isBuiltInSyntax (Name {n_sort = WiredIn _ _ _ BuiltInSyntax}) = True
145 isBuiltInSyntax other = False
147 isExternalName (Name {n_sort = External _ _}) = True
148 isExternalName (Name {n_sort = WiredIn _ _ _ _}) = True
149 isExternalName other = False
151 isInternalName name = not (isExternalName name)
153 nameParent_maybe :: Name -> Maybe Name
154 nameParent_maybe (Name {n_sort = External _ p}) = p
155 nameParent_maybe (Name {n_sort = WiredIn _ p _ _}) = p
156 nameParent_maybe other = Nothing
158 nameParent :: Name -> Name
159 nameParent name = case nameParent_maybe name of
160 Just parent -> parent
163 isImplicitName :: Name -> Bool
164 -- An Implicit Name is one has a parent; that is, one whose definition
165 -- derives from the parent thing
166 isImplicitName name = isJust (nameParent_maybe name)
168 nameModule name = nameModule_maybe name `orElse` pprPanic "nameModule" (ppr name)
169 nameModule_maybe (Name { n_sort = External mod _}) = Just mod
170 nameModule_maybe (Name { n_sort = WiredIn mod _ _ _}) = Just mod
171 nameModule_maybe name = Nothing
173 nameIsLocalOrFrom from name
174 | isExternalName name = from == nameModule name
177 isTyVarName :: Name -> Bool
178 isTyVarName name = isTvOcc (nameOccName name)
180 isSystemName (Name {n_sort = System}) = True
181 isSystemName other = False
185 %************************************************************************
187 \subsection{Making names}
189 %************************************************************************
192 mkInternalName :: Unique -> OccName -> SrcLoc -> Name
193 mkInternalName uniq occ loc = Name { n_uniq = uniq, n_sort = Internal, n_occ = occ, n_loc = loc }
194 -- NB: You might worry that after lots of huffing and
195 -- puffing we might end up with two local names with distinct
196 -- uniques, but the same OccName. Indeed we can, but that's ok
197 -- * the insides of the compiler don't care: they use the Unique
198 -- * when printing for -ddump-xxx you can switch on -dppr-debug to get the
199 -- uniques if you get confused
200 -- * for interface files we tidyCore first, which puts the uniques
201 -- into the print name (see setNameVisibility below)
203 mkExternalName :: Unique -> Module -> OccName -> Maybe Name -> SrcLoc -> Name
204 mkExternalName uniq mod occ mb_parent loc
205 = Name { n_uniq = uniq, n_sort = External mod mb_parent,
206 n_occ = occ, n_loc = loc }
208 mkWiredInName :: Module -> OccName -> Unique
209 -> Maybe Name -> TyThing -> BuiltInSyntax -> Name
210 mkWiredInName mod occ uniq mb_parent thing built_in
211 = Name { n_uniq = uniq,
212 n_sort = WiredIn mod mb_parent thing built_in,
213 n_occ = occ, n_loc = wiredInSrcLoc }
215 mkSystemName :: Unique -> OccName -> Name
216 mkSystemName uniq occ = Name { n_uniq = uniq, n_sort = System,
217 n_occ = occ, n_loc = noSrcLoc }
219 mkSystemVarName :: Unique -> FastString -> Name
220 mkSystemVarName uniq fs = mkSystemName uniq (mkVarOccFS fs)
222 mkSysTvName :: Unique -> FastString -> Name
223 mkSysTvName uniq fs = mkSystemName uniq (mkOccNameFS tvName fs)
225 mkFCallName :: Unique -> String -> Name
226 -- The encoded string completely describes the ccall
227 mkFCallName uniq str = Name { n_uniq = uniq, n_sort = Internal,
228 n_occ = mkVarOcc str, n_loc = noSrcLoc }
230 mkIPName :: Unique -> OccName -> Name
232 = Name { n_uniq = uniq,
239 -- When we renumber/rename things, we need to be
240 -- able to change a Name's Unique to match the cached
241 -- one in the thing it's the name of. If you know what I mean.
242 setNameUnique name uniq = name {n_uniq = uniq}
244 tidyNameOcc :: Name -> OccName -> Name
245 -- We set the OccName of a Name when tidying
246 -- In doing so, we change System --> Internal, so that when we print
247 -- it we don't get the unique by default. It's tidy now!
248 tidyNameOcc name@(Name { n_sort = System }) occ = name { n_occ = occ, n_sort = Internal}
249 tidyNameOcc name occ = name { n_occ = occ }
251 localiseName :: Name -> Name
252 localiseName n = n { n_sort = Internal }
256 %************************************************************************
258 \subsection{Predicates and selectors}
260 %************************************************************************
263 hashName :: Name -> Int
264 hashName name = getKey (nameUnique name)
268 %************************************************************************
270 \subsection[Name-instances]{Instance declarations}
272 %************************************************************************
275 cmpName n1 n2 = n_uniq n1 `compare` n_uniq n2
279 instance Eq Name where
280 a == b = case (a `compare` b) of { EQ -> True; _ -> False }
281 a /= b = case (a `compare` b) of { EQ -> False; _ -> True }
283 instance Ord Name where
284 a <= b = case (a `compare` b) of { LT -> True; EQ -> True; GT -> False }
285 a < b = case (a `compare` b) of { LT -> True; EQ -> False; GT -> False }
286 a >= b = case (a `compare` b) of { LT -> False; EQ -> True; GT -> True }
287 a > b = case (a `compare` b) of { LT -> False; EQ -> False; GT -> True }
288 compare a b = cmpName a b
290 instance Uniquable Name where
291 getUnique = nameUnique
293 instance NamedThing Name where
298 %************************************************************************
300 \subsection{Pretty printing}
302 %************************************************************************
305 instance Outputable Name where
306 ppr name = pprName name
308 instance OutputableBndr Name where
309 pprBndr _ name = pprName name
311 pprName (Name {n_sort = sort, n_uniq = uniq, n_occ = occ})
312 = getPprStyle $ \ sty ->
314 WiredIn mod _ _ builtin -> pprExternal sty uniq mod occ True builtin
315 External mod _ -> pprExternal sty uniq mod occ False UserSyntax
316 System -> pprSystem sty uniq occ
317 Internal -> pprInternal sty uniq occ
319 pprExternal sty uniq mod occ is_wired is_builtin
320 | codeStyle sty = ppr_z_module mod <> char '_' <> ppr_z_occ_name occ
321 -- In code style, always qualify
322 -- ToDo: maybe we could print all wired-in things unqualified
323 -- in code style, to reduce symbol table bloat?
324 | debugStyle sty = ppr mod <> dot <> ppr_occ_name occ
325 <> braces (hsep [if is_wired then ptext SLIT("(w)") else empty,
326 pprNameSpaceBrief (occNameSpace occ),
328 | BuiltInSyntax <- is_builtin = ppr_occ_name occ
329 -- never qualify builtin syntax
330 | unqualStyle sty mod occ = ppr_occ_name occ
331 | otherwise = ppr mod <> dot <> ppr_occ_name occ
333 pprInternal sty uniq occ
334 | codeStyle sty = pprUnique uniq
335 | debugStyle sty = ppr_occ_name occ <> braces (hsep [pprNameSpaceBrief (occNameSpace occ),
337 | dumpStyle sty = ppr_occ_name occ <> char '_' <> pprUnique uniq
338 -- For debug dumps, we're not necessarily dumping
339 -- tidied code, so we need to print the uniques.
340 | otherwise = ppr_occ_name occ -- User style
342 -- Like Internal, except that we only omit the unique in Iface style
343 pprSystem sty uniq occ
344 | codeStyle sty = pprUnique uniq
345 | debugStyle sty = ppr_occ_name occ <> char '_' <> pprUnique uniq
346 <> braces (pprNameSpaceBrief (occNameSpace occ))
347 | otherwise = ppr_occ_name occ <> char '_' <> pprUnique uniq
348 -- If the tidy phase hasn't run, the OccName
349 -- is unlikely to be informative (like 's'),
350 -- so print the unique
352 ppr_occ_name occ = ftext (occNameFS occ)
353 -- Don't use pprOccName; instead, just print the string of the OccName;
354 -- we print the namespace in the debug stuff above
356 -- In code style, we Z-encode the strings. The results of Z-encoding each FastString are
357 -- cached behind the scenes in the FastString implementation.
358 ppr_z_occ_name occ = ftext (zEncodeFS (occNameFS occ))
359 ppr_z_module mod = ftext (zEncodeFS (moduleFS mod))
363 %************************************************************************
365 \subsection{Overloaded functions related to Names}
367 %************************************************************************
370 class NamedThing a where
371 getOccName :: a -> OccName
374 getOccName n = nameOccName (getName n) -- Default method
378 getSrcLoc :: NamedThing a => a -> SrcLoc
379 getOccString :: NamedThing a => a -> String
381 getSrcLoc = nameSrcLoc . getName
382 getOccString = occNameString . getOccName